Ok, let me put it another way. If there is a variation for the amount of knowledge the brain can consume from human to human, assuming they're "healthy", it's gonna be something like Infinity x 99, infinity x 8, Infinity / 2. Whatever it is, it'll be a limit that's way beyond what a human being could ever reach in a lifetime.

Optimism is good, but at this point, you're driving past believing in the intrinsic awesome of human beings into the territory of magical thinking.

"Amount of knowledge" isn't a useful metric, as anyone in pedagogy can tell you. It's not even about "healthiness", which is meaningless, or disability, which is less meaningless. Brains are not hard disks. They aren't knowledge storage machines. That's just one of its minor functions.

You're completely right. This discussion is almost impossible since, for the human brain, I can't define "knowledge", "capacity", "limit", "intellect". I mean really, what does it mean for a human brain to reach capacity anyway? What function is it not able to do once it reaches that point? What does it mean to be smart or intellectual? Do we all agree that Stephen Hawking is those things? Why? I don't know and I can't even begin to debate it, I'm not smart enough. ;)

> I don't know and I can't even begin to debate it, I'm not smart enough.

Well, no. You lack the knowledge for having a useful discussion about it. Spend time brushing up on pedagogical techniques, neuroscience, cognitive science, psychology: all the fields that touch on growth in the mental dimensions of a human being. My own expertise is pretty minimal, but just seeing the cutting edge of the research is fascinating and can help keep you honest when making claims.

This isn't a political/stylistic discussion. It rests on factual foundations, where people have actually looked at fMRIs or done longitudinal studies on schools or scrutinized the brain composition of different age groups.

Science doesn't fully understand the human brain so I cannot agree that intelligence can be fully measured by any scientific means today. We have some tests, but the value of them is debated.

So you don't believe that there's a spectrum of disability? You're either intellectually disabled to the point of not being able to dress yourself... or you're a potential Einstein - nothing in between?

It doesn't seem like I can reply to smtddr's sibling comment here (probably nested too deep?). So here's my two cents:

I agree that in context of memory, the brain's capacity does appear limitless. However, the brain's capacity to process all of the information that it's exposed to is quite limited. For example, for most people, working memory is limited to 7 items plus/minus 2. One part of a standard cognitive test is to expose the subject to a list of numbers, and after hiding the numbers, ask the subject to repeat them back to you (and again, but backwards). A similar test of memory is to ask a subject to remember a list of items, then ask a series of other questions, then ask the subject to repeat the same list some time later. Some people do pretty well at these tests; some don't (approximating a normal distribution in ). So while it's theoretically possible that all subjects do have all of the numbers stored in their brain, it's quite clear that there's differing capability at least in memory encoding and/or retrieval.

I guess I also wanted to mention the concept of saliency. Different people will pay attention to different things even if all of the people are exposed to exactly the same stimuli. This is important because the brain only encodes to memory what it finds particularly important and/or interesting (i.e. salient). This can be trained to a degree: more experienced or trained people will be able to detect what's important, like a soldier being better able to "sense" the presence of an IED in a warzone. So even if everyone has exactly the same memory capacity, there'd still be variation in how well the brain itself decides to use that capacity.

> It doesn't seem like I can reply to smtddr's sibling comment here (probably nested too deep?).

OT technical note.

The reason you do not see a "reply" link is because you viewed the comment within X minutes of its posting. HN disables the reply link for that period. However, if you click on the permalink (the "link" text), you will still get a usable text box for replying.

My strategy is generally to do this, but sometimes I actually just refresh to pick up any new contextual comments.

I can't define what it means to be "Einstein". I can only say that "capacity for knowledge" in a "healthy" human brain is well beyond what it could ever be exposed to in a lifetime. Note that when I say "capacity", I thinking in terms of a computer harddrive(which is questionable). No "healthy" human being can fill up their brain within a lifetime.

This discussion is pretty difficult in that there are things we can't define. I don't even know if we're all talking about the same thing when we say "knowledge" and we can't define "healthy", and the term "capacity" for the human brain is assuming we all believe the human brain really does have a limit. I can only assume there is some kind of limit in the same way I assume if I traveled in a straight line forever I'd eventually reach the end of the universe. It's just imcomprehendably large and nothing we do in a lifetime, currently 100 years or so, will reach that limit.